Mechanism of suppression of Auger recombination processes in type-II heterostructures

Abstract

The mechanism of Auger recombination in type-II heterostructures is studied theoretically. It is shown that the Auger recombination rate is a power function of temperature rather than an exponential function as in bulk materials. The feasibility of suppression of the Auger recombination process in the type-II heterostructures is demonstrated. The possibility of controlling the Auger recombination rate is shown to be very important for development of optoelectronic devices with improved characteristics.

Observation of suppressed Auger mechanism in type-I quantum well structures with delocalized electron-hole wavefunctions

“…It is important to note that in Type-II structures, the Auger recombination can be further suppressed by the separation of the electron and hole wavefunctions that reduces the overlap integral. 11,15 Here we show that the same mechanism is responsible for significantly lower Auger recombination rate compared to other Type-I MQWs without delocalized electron and hole wavefunctions. Each of the five periods of the grown MQW structure consists of 17 nm of InAlAs as a barrier for electrons, 18 nm of InGaAsP with a cut off wavelength of 1.4 µm, 1 nm of InAlAs, 3nm of InGaAs and 17 nm of InP as a barrier for holes.…”

“…11 In conclusion, we characterized the Auger recombination mechanism in a Type-I quantum well structure with delocalized electron hole wavefunctions. We used the excitation-dependent PL measurements to extract the Auger recombination coefficients from 78 K up to room temperature.…”

“…This effect can be employed to obtain excellent electro-absorption properties such as high on/off modulation contrast and enhanced optical modulation sensitivity to the externally applied voltages. 8,9 The non-threshold Auger mechanism has power-law temperature dependence and is predicted in heterostructures 10,11 where the momentum conservation law is violated orthogonal to the growth direction. In this regard, the dominant CCHC Auger mechanism in QW structures can be decomposed into two main parts: 11 (a) contribution of large momentum transfer to the electron in the conduction band ∼  (2m h E g ), where E g is the bandgap energy and m h is the heavy hole effective mass, and (b) contribution from small transferred momentum from heavy holes ∼  (2m h K B T), where T is the temperature and K B is the Boltzmann constant.…”

Novel type-II material system for laser applications in the near-infrared regime

“…Thus, the gain can be optimized while, at the same time, Auger losses can be controlled. 9 Pioneering work in this field has been presented by Meyer et al, Kudo et al, and Vurgaftman et al who introduced type-II "W"-material systems as active region of a laser setup. [10][11][12] These structures consist of a sandwich configuration involving two different materials (see Fig.…”

Variational approach to the calculation of the lowest Wannier exciton state in wide type-II single semiconductor quantum wells

“…Quantum heterostructures with the type-II band alignment has been investigated for a long time due to promising physical properties: a long recombination lifetime as compared to that of type-I systems, lower exciton binding energy, strong dependence of the emission energy and oscillator strength on the well width [1][2][3], suppression of the Auger recombination rate [4], enhanced Stark-effect [5,6] and others. These features are caused, first of all, by the band alignment between materials of the structure layers, which determines the spatial distribution of excited charge carriers.…”